using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace RUNPCCPUTest
{
    class Program
    {
        private static String _doc =
        "CGAATCTAAAAATAGATTCGGACGTGATGTAGTCGTACAAATGAAAAAGTAAGCC";
        private static int ITERATIONS = 1000000;

        public static void Main()
        {
            String nl = Environment.NewLine;
            String[] colorNames = ConsoleColor.GetNames(typeof(ConsoleColor));
            Console.ForegroundColor = (ConsoleColor)Enum.Parse(typeof(ConsoleColor),"White");
            Console.WriteLine("此範例會計算從1000000~2000000運算字串配對,等候到在2000000找到結果才會結束"+"\r\n");
            Console.ResetColor();

            //設定開始時間
            long start = System.DateTime.Now.Ticks / 10000;
            long end;
            int length = 1;
            int x = 9;

            for (int i = ITERATIONS; i <= ITERATIONS * 2; i++)
            {
                length = (int)(Math.Log((double)i) / Math.Log(4));
                String matchthis = generateWord(i, length + 1);
                Regex regexpr = new Regex(matchthis, RegexOptions.Compiled);
                Boolean b = regexpr.IsMatch(_doc);

                //成功配對字串
                if (b)
                {
                    //設定結束時間
                    end = System.DateTime.Now.Ticks / 10000;
                    Console.ForegroundColor = (ConsoleColor)Enum.Parse(typeof(ConsoleColor), colorNames[x]);
                    x++;
                    if (x == 15)
                        x = 9;
                    Console.WriteLine("在 {0} 找到 {1},共花了 {2} 毫秒.",
                    i, matchthis, end - start);
                    Console.ResetColor();
                }

            }
            //設定結束時間
            end = System.DateTime.Now.Ticks / 10000;
            Console.ForegroundColor = (ConsoleColor)Enum.Parse(typeof(ConsoleColor), "White");
            Console.WriteLine("\r\n" + ".NET 常規表示法運算共花了 {0} 毫秒", end - start);
            Console.ResetColor();
        }

        /// <summary>
        /// 產生字串
        /// </summary>
        /// <param name="value"></param>
        /// <param name="length"></param>
        /// <returns></returns>
        public static String generateWord(int value, int length)
        {
            StringBuilder buf = new StringBuilder();
            int current = value;
            for (int i = 0; i < length; i++)
            {
                int v = current % 4;
                current = current / 4;
                buf.Append(convert(v));
            }
            return buf.ToString();
        }

        /// <summary>
        /// 轉換為英文字母
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        private static String convert(int value)
        {
            switch (value)
            {
                case 0: return "A";
                case 1: return "G";
                case 2: return "T";
                case 3: return "C";
                default:
                    return "0";
            }
        }
    }
}